Conventional air conditioning systems generally comprise a compressor, a condenser coil, a condenser fan for passing air through the condenser coil, an evaporator coil, and an evaporator blower for passing air through the evaporator coil. The condenser coil and the evaporator coil are each designed as heat exchangers with internal tubing for carrying refrigerant. The major components of the air conditioning system can be grouped and located in different manners, but two arrangements are most prevalent.
A “split-system” is generally an air conditioning system in which the compressor, the condenser coil, and the condenser fan are colocated within a single housing, often referred to as a condensing unit. In the split-system, the evaporator coil and the evaporator blower are also collocated within a single housing, often referred to as an air handling unit or air handler. Some air handling units or air handlers comprise heat generators such as electrically resistive heating elements and/or gas furnace elements so that the evaporator coil and the heat generators are both in an airflow path of the evaporator blower. In most applications of a split-system, the condensing unit is located outside the space to be temperature controlled while the air handling unit is located within the space to be temperature controlled. More specifically, it is common for the condensing unit to be located outside the building or structure that is to be temperature controlled while the air handling unit is typically located within a closet, attic, or other location within the building.
Alternatively, a conventional air conditioning system may be configured as a “package unit” where all of the components of the air conditioning system are colocated within a single housing. Package units are typically, but not necessarily, installed in a location exterior to the space to be temperature controlled.
Regardless of the type of air conditioning system, the principles of operation remain the same. Generally, the compressor operates to compress refrigerant into a hot and high pressure gas, which is passed through the internal tubing of the condenser coil. As the refrigerant is passed through the condenser coil, the condenser fan operates to pass ambient air across the condenser coil, thereby removing heat from the refrigerant and condensing the refrigerant into liquid form. The liquid refrigerant is then delivered to the evaporator coil. Upon reaching the evaporator coil, the liquid refrigerant is passed through a flow restriction device, which causes the refrigerant to transform into a cold and low pressure gas. As the cold gas is passed through the evaporator coil, the evaporator blower passes ambient air across the evaporator coil, thereby providing a cooling and dehumidifying effect to the ambient air, which is then distributed to the space to be temperature controlled.